subr_module.c revision 209390 
1/*-
2 * Copyright (c) 1998 Michael Smith
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sys/kern/subr_module.c 209390 2010-06-21 09:55:56Z ed $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/linker.h>
33
34/*
35 * Preloaded module support
36 */
37
38caddr_t	preload_metadata;
39
40/*
41 * Search for the preloaded module (name)
42 */
43caddr_t
44preload_search_by_name(const char *name)
45{
46    caddr_t	curp;
47    uint32_t	*hdr;
48    int		next;
49
50    if (preload_metadata != NULL) {
51
52	curp = preload_metadata;
53	for (;;) {
54	    hdr = (uint32_t *)curp;
55	    if (hdr[0] == 0 && hdr[1] == 0)
56		break;
57
58	    /* Search for a MODINFO_NAME field */
59	    if ((hdr[0] == MODINFO_NAME) &&
60		!strcmp(name, curp + sizeof(uint32_t) * 2))
61		return(curp);
62
63	    /* skip to next field */
64	    next = sizeof(uint32_t) * 2 + hdr[1];
65	    next = roundup(next, sizeof(u_long));
66	    curp += next;
67	}
68    }
69    return(NULL);
70}
71
72/*
73 * Search for the first preloaded module of (type)
74 */
75caddr_t
76preload_search_by_type(const char *type)
77{
78    caddr_t	curp, lname;
79    uint32_t	*hdr;
80    int		next;
81
82    if (preload_metadata != NULL) {
83
84	curp = preload_metadata;
85	lname = NULL;
86	for (;;) {
87	    hdr = (uint32_t *)curp;
88	    if (hdr[0] == 0 && hdr[1] == 0)
89		break;
90
91	    /* remember the start of each record */
92	    if (hdr[0] == MODINFO_NAME)
93		lname = curp;
94
95	    /* Search for a MODINFO_TYPE field */
96	    if ((hdr[0] == MODINFO_TYPE) &&
97		!strcmp(type, curp + sizeof(uint32_t) * 2))
98		return(lname);
99
100	    /* skip to next field */
101	    next = sizeof(uint32_t) * 2 + hdr[1];
102	    next = roundup(next, sizeof(u_long));
103	    curp += next;
104	}
105    }
106    return(NULL);
107}
108
109/*
110 * Walk through the preloaded module list
111 */
112caddr_t
113preload_search_next_name(caddr_t base)
114{
115    caddr_t	curp;
116    uint32_t	*hdr;
117    int		next;
118
119    if (preload_metadata != NULL) {
120
121	/* Pick up where we left off last time */
122	if (base) {
123	    /* skip to next field */
124	    curp = base;
125	    hdr = (uint32_t *)curp;
126	    next = sizeof(uint32_t) * 2 + hdr[1];
127	    next = roundup(next, sizeof(u_long));
128	    curp += next;
129	} else
130	    curp = preload_metadata;
131
132	for (;;) {
133	    hdr = (uint32_t *)curp;
134	    if (hdr[0] == 0 && hdr[1] == 0)
135		break;
136
137	    /* Found a new record? */
138	    if (hdr[0] == MODINFO_NAME)
139		return curp;
140
141	    /* skip to next field */
142	    next = sizeof(uint32_t) * 2 + hdr[1];
143	    next = roundup(next, sizeof(u_long));
144	    curp += next;
145	}
146    }
147    return(NULL);
148}
149
150/*
151 * Given a preloaded module handle (mod), return a pointer
152 * to the data for the attribute (inf).
153 */
154caddr_t
155preload_search_info(caddr_t mod, int inf)
156{
157    caddr_t	curp;
158    uint32_t	*hdr;
159    uint32_t	type = 0;
160    int		next;
161
162    curp = mod;
163    for (;;) {
164	hdr = (uint32_t *)curp;
165	/* end of module data? */
166	if (hdr[0] == 0 && hdr[1] == 0)
167	    break;
168	/*
169	 * We give up once we've looped back to what we were looking at
170	 * first - this should normally be a MODINFO_NAME field.
171	 */
172	if (type == 0) {
173	    type = hdr[0];
174	} else {
175	    if (hdr[0] == type)
176		break;
177	}
178
179	/*
180	 * Attribute match? Return pointer to data.
181	 * Consumer may safely assume that size value precedes
182	 * data.
183	 */
184	if (hdr[0] == inf)
185	    return(curp + (sizeof(uint32_t) * 2));
186
187	/* skip to next field */
188	next = sizeof(uint32_t) * 2 + hdr[1];
189	next = roundup(next, sizeof(u_long));
190	curp += next;
191    }
192    return(NULL);
193}
194
195/*
196 * Delete a preload record by name.
197 */
198void
199preload_delete_name(const char *name)
200{
201    caddr_t	curp;
202    uint32_t	*hdr;
203    int		next;
204    int		clearing;
205
206    if (preload_metadata != NULL) {
207
208	clearing = 0;
209	curp = preload_metadata;
210	for (;;) {
211	    hdr = (uint32_t *)curp;
212	    if (hdr[0] == 0 && hdr[1] == 0)
213		break;
214
215	    /* Search for a MODINFO_NAME field */
216	    if (hdr[0] == MODINFO_NAME) {
217		if (!strcmp(name, curp + sizeof(uint32_t) * 2))
218		    clearing = 1;	/* got it, start clearing */
219		else if (clearing)
220		    clearing = 0;	/* at next one now.. better stop */
221	    }
222	    if (clearing)
223		hdr[0] = MODINFO_EMPTY;
224
225	    /* skip to next field */
226	    next = sizeof(uint32_t) * 2 + hdr[1];
227	    next = roundup(next, sizeof(u_long));
228	    curp += next;
229	}
230    }
231}
232
233/* Called from locore on i386.  Convert physical pointers to kvm. Sigh. */
234void
235preload_bootstrap_relocate(vm_offset_t offset)
236{
237    caddr_t	curp;
238    uint32_t	*hdr;
239    vm_offset_t	*ptr;
240    int		next;
241
242    if (preload_metadata != NULL) {
243
244	curp = preload_metadata;
245	for (;;) {
246	    hdr = (uint32_t *)curp;
247	    if (hdr[0] == 0 && hdr[1] == 0)
248		break;
249
250	    /* Deal with the ones that we know we have to fix */
251	    switch (hdr[0]) {
252	    case MODINFO_ADDR:
253	    case MODINFO_METADATA|MODINFOMD_SSYM:
254	    case MODINFO_METADATA|MODINFOMD_ESYM:
255		ptr = (vm_offset_t *)(curp + (sizeof(uint32_t) * 2));
256		*ptr += offset;
257		break;
258	    }
259	    /* The rest is beyond us for now */
260
261	    /* skip to next field */
262	    next = sizeof(uint32_t) * 2 + hdr[1];
263	    next = roundup(next, sizeof(u_long));
264	    curp += next;
265	}
266    }
267}
268